Multi feed bait system is the way to go. I was a Orkin man for a good while and that is the best way to get rid of a issue. But you must also take in account your environment, If you live in the woods or by fields or have a neighbor that does not maintain the property you will always have an issue. Oh ya the water thing is a myth they don't get thirsty from eating the poison, the poison deprives their body from retaining vitamin K and thats how they die. They must eat 1/10th their body weight to have any effect, thats why poison its much safer than most would believe. If you have a 20 lb dog and it happens to get into it then it has to eat 2 lbs which is way more than you will ever need to put out for mice.